I spent most of my time growing up doing two things, going to school and playing sports. I made many fond memories -- mostly from the latter :) -- and learned more than a few lessons over that time. Of all of those lessons, there was one in particular that stuck out in both the classroom and on the baseball diamond: Sometimes you have to get back to the basics.
In that vein, I think it is time to revisit the basics of WebSphere CloudBurst. In revisiting the basics, I am not talking about the technical basics of the appliance. Rather, I am talking about revisiting exactly why WebSphere CloudBurst exists in the first place. In other words, let's take a look at the problem domains WebSphere CloudBurst addresses, and let's discuss a little bit about how the appliance does so.
One of my favorite books from childhood is If You Give a Mouse a Cookie. Although targeted at children, the book illustrates a frequently occurring human behavior that is important for all of us understand. That behavior is the tendency for escalating expectations. The book offers this up by starting out with the simple action of giving a mouse a cookie. The mouse in turn asks for a glass of milk, various flavors of cookies, and on and on, until the mouse circles back to asking for another cookie.
Nearly all of us exhibit this same kind of behavior, and it can often produce positive results. In particular, in IT we always push for the next best thing or a slightly better outcome. Personally, I am no stranger to this behavior because I experience it from WebSphere CloudBurst users quite frequently. In these cases, it usually revolves around one particular outcome: speed of deployment.
Bar none, users of WebSphere CloudBurst are experiencing unprecedented deployment times for the environments they dispense through the appliance. The fact that we say you can deploy meaningful enterprise application environments in a matter of minutes is far beyond just marketing literature. Our users prove it everyday. However, just because they are deploying things faster than ever does not mean they are content to rest on those achievements. They want to push the envelope, and I love it.
For our users looking to achieve even speedier deployment times, I offer up one reminder and one tip. First, analyze all of your script packages to ensure you are using the right means of customization. If you have some scripts that run for considerably longer than most other script packages, you may want to at least consider applying that customization by creating a custom image. You still need to adhere to the customization principles outlined here, but you may benefit from applying the customization in an image once and avoiding the penalty for applying it during every deployment. You may also be able to break this customization out with a combination of a custom image and script packages. For instance, instead of having a script that installs and configures monitoring agents, you may install the agents in a custom image and configure them during deployment. Being selective about how and when you apply customizations can go a long way in improving your deployment times.
In addition to the reminder above, I also have a tip. Take a look at all of the script packages you use in pattern deployments and look to see if there are any that you can apply in an asynchronous manner. In other words, identify customizations that need to start, but not necessarily complete as part of the deployment process. Going back to our example of configuring monitoring agents during the deployment process, it may be important to kick off the configuration script during deployment, but is it crucial to wait on the results? Maybe not. If it is not, consider defining the executable argument in your script package in a manner that kicks off the execution and proceeds -- i.e. nohup executable command &. This approach can save deployment time in certain situations.
My advice to users of WebSphere CloudBurst: keep pushing your deployment process! Pare as many minutes off the process as you can. I hope that the tips above help in that regard, and be sure to pass along other techniques that you have found helpful.
Though I feel like we've come a long way in some of the initial confusion surrounding IBM CloudBurst and WebSphere CloudBurst, I still get quite a few basic questions on the solutions. The two most common questions are, 'Are they different products?', and 'Can/should I use them together?'. I put together a really brief overview that answers these questions and talks about the basics of the combined solution. I hope it provides a good introduction!
When I talk with WebSphere CloudBurst users, the topic of custom virtual images comes up frequently. In some cases they simply want to customize a shipped IBM Hypervisor Edition, and in other cases they want to create a completely custom image. Creating a customized version of an IBM Hypervisor Edition is relatively easy since we give you extend & capture in WebSphere CloudBurst. Creating a completely custom image has historically been a bit tougher, mostly owing ot the fact that there was not a standard tool or process for image assembly. I am happy to say that today's publication of the IBM Image Construction and Composition Tool changes all that.
Watch a demo of the IBM Image Construction and Composition Tool
The primary purpose of the Image Construction and Composition Tool is to enable a modular approach to virtual image construction, while taking into account the typical division of responsibilities within an organization. The tool allows the right people within an organization to contribute their specialized knowledge as appropriate to the virtual image creation process. This means OS teams can handle the OS and software teams can handle the appropriate software. A separate image builder can then use both OS and software components to meet the needs of users within the organization. Best of all, the image builder does not need intimate knowledge of how to install or configure any of the components in the image. They simply need to know which OS and software components to use.
When using the Image Construction and Composition Tool, you start by defining the base operating system you wish to use for your images. You can do this by importing an existing virtual image with an OS already installed, providing an ISO for the OS, or pointing to a base OS image on the IBM Cloud. The bottom line is that you have necessary flexibility to start with your certified or ‘golden’ operating system build. Once you have the base OS image defined in the Image Construction and Composition Tool, you can start defining custom software for use in the images you will compose.
In the tool, bundles represent the software you wish to install within a virtual image. The definition of a bundle contains two major parts: Installation and Configuration. The installation component of a bundle tells the Image Construction and Composition Tool how to install your software into the virtual image. You provide a script or set of scripts that install the necessary components into your image, and you direct the tool to call these scripts. These tasks run once during the initial creation of the virtual image, thus allowing you to capture large binaries, long-running installation tasks, or other necessary actions directly into your image.
The configuration section of a bundle defines actions that configure the software installed into the image. Like with the installation tasks, you provide a script or set of scripts for configuration tasks. Unlike installation tasks that run exactly once, configuration scripts become part of the image’s activation framework and as such, run during each image deployment. Using the tool, you can define input parameters for configuration scripts and optionally expose them so that users can provide values for the parameters at image deploy-time. Configuration tasks are important in providing flexibility that allows users to leverage a single virtual image for a number of different deployment scenarios.
Once you have your base OS image and one or more bundles defined in the Image Construction and Composition Tool, you can compose a virtual image. To compose a virtual image, you extend the base OS image and add any number of bundles into the new image. A base OS image plus a set of bundles defines a unique image.
After you define the image you want to construct, you initiate a synchronize action in the Image Construction and Composition Tool. When you start the synchronize action, the tool first creates a virtual machine in either a VMware or IBM Cloud environment (based on how you configured the tool). Next, the installation tasks of each bundle you included in the virtual image run to install the required software. Finally, the tool copies the configuration scripts from each bundle into the virtual machine and adds them to the image’s activation framework. This ensures the automatic invocation of all configuration scripts during subsequent image deployments.
Once the image is in the synchronized state, you can capture it. Capturing the image results in the creation of a virtual image based on the state of the synchronized virtual machine. The tool also automates the generation of metadata that becomes part of the virtual image package. When the capture of the virtual image completes, you can export it from the Image Construction and Composition Tool and deploy it using WebSphere CloudBurst, Tivoli Provisioning Manager, or the IBM Cloud.
I am excited for users to get their hands on the Image Construction and Composition Tool. I believe it represents the first big step in helping users to design and construct more sustainable virtual images. Did I mention it is completely free to download and use? Visit the Image Construction and Composition Tool website for more details and a download link. I look forward to your comments and feedback.
Since bundles are such a core component of the IBM Image Construction and Composition Tool, I thought it would help to take a closer, more thorough look at them than I did in my post last week (if you have not already, I suggest reading the overview post before continuing). To help us in our closer examination, we will consider an example bundle I built using the IBM Image Construction and Composition Tool. The example bundle I built encapsulates the logic to install and configure WebSphere Application Server Community Edition. Let's take this step by step.
The first part of the bundle is the General section. This section allows you to provide a name and description for the bundle, the bundle ID and version, and the products represented by the bundle.
The next section of a bundle is the Requirements section. In this section, you can define the operating system and software requirements for your bundle. In the OS section, you specify the type, distribution, and version level of the OS your bundle requires. In the software section, you can indicate that your bundle requires other bundles defined in the IBM Image Construction and Composition Tool. You do this by providing the bundle ID for required bundles.
Next, we move on to the Install section of the bundle. Two major subsections make up this section. The first subsection is the Files to Copy section. Here, you provide files, via a file upload dialog or by providing a URI, and you specify a destination directory. When you add a bundle to an image and initiate the synchronization process, the IBM Image Construction and Composition Tool will automatically copy the files you list here to the specified destination directory on the virtual machine. In the sample WebSphere Application Server Community Edition bundle, I specify a single install.sh file to copy to the virtual machine.
The second major subsection of the Install section is the Command subsection. In this section, you will specify the installation command that the IBM Image Construction and Composition Tool should automatically invoke during the synchronization process. Additionally, you can define variables that you want to make available to your installation scripts. The tool makes these available as environment variables for the process within which your script runs. In the sample bundle, I tell the Image Construction and Composition Tool to invoke the install.sh script specified above, and I define parameters that specify the location of the binaries to install, the location to install the binaries on disk, and more.
The next section in a bundle is the Configuration section. The configuration section allows you to define configuration operations that provide actions that execute for each deployment of an image containing the bundle. You can define 0 to N configuration operations in a bundle, and each configuration operation definition contains three major subsections. The first is the Files to Copy subsection. This subsection is similar to the Files to Copy subsection in the Install section. You provide files or file URIs and you provide a destination directory to which the tool will copy the file. The WebSphere Application Server Community Edition bundle contains a single configuration operation called ConfigWASCE. In the Files to Copy section, I define a single file to copy into the image's activation engine directory.
The second major subsection in the configuration operation definition is the Command subsection. Like the Command subsection in the Install section of the bundle, you specify a command to execute and optionally associate variables with the command. There is a key difference between the command definition for configuration operations as opposed to installation operations. The Image Construction and Composition Tool invokes the command you specify for installation operations exactly ONCE at image creation (synchronization) time. On the other hand, commands you specify in the configuration operation definition execute EACH time someone deploys an image containing your bundle. In the sample bundle, my ConfigWASCE.sh script will automatically execute for each deployment. The tool will package the image in such a way that ensures the automatic passing of parameters defined in the Arguments list (including num_servers, WASCE_HOME, and more) to the ConfigWASCE.sh script.
The final major subsection of a configuration operation definition is the Dependencies section. This allows you to define other services on which your configuration operation is dependent. This can include other configuration operations in the same or other bundles, and it can include general operating system services. The WebSphere Application Server Community Edition sample bundle includes a few dependencies.
The Install and Configuration sections are really the meat of your bundle, but there is more. There is a Firewall section that allows you to define port ranges and associated protocols that the IBM Image Construction and Composition Tool should ensure are open when provisioning an image containing your bundle. Currently, the tool supports firewall configuration data when building images for the IBM Cloud. The Reset section of the bundle allows you to define tasks that should execute when capturing the image back into the Image Construction and Composition Tool (after synchronziation completes). This allows you to clean up the state of the image after the install completes. Reset configuration is not currently available in the alphaWorks version of the tool. Finally, there is a License section where you can define software licenses associated with your bundle. The tool automatically adds these licenes to the constructed image's metadata, thereby allowing deployment tools to prompt the user to accept all pertinent licenses. The WebSphere Application Server Community Edition sample bundle defines a product license.
Of course, once the bundle definition is complete, you can leverage it to compose and produce an image that you can use in WebSphere CloudBurst, Tivoli Provisioning Manager, or on the IBM Cloud. In the case of the WebSphere Application Server Community Edition sample bundle, I used it to create an image that I loaded into WebSphere CloudBurst and used to build patterns.
I hope this helps to provide a better idea of what bundles are all about in the Image Construction and Composition Tool. Don't forget to take a look at the overview demo and stay tuned for more to come about this new tool!
In last week's post, I put the spotlight on various aspects of bundles in the Image Construction and Composition Tool. I finished with a look at a WebSphere CloudBurst virtual image created from the bundle. However, you do not just magically go from a bundle to an image that you can use in WebSphere CloudBurst, Tivoli Provisioning Manager, or on the IBM Cloud. Today, I want to show you how to go from a bundle to a custom virtual image using the IBM Image Construction and Composition Tool.
Once you have defined at least one bundle and one base operating system image, you are ready to compose a custom image. We already talked about creating a bundle, but the base operating system image is a new topic. You can do this by either starting from ISO and kickstart configuration files, or you can import an existing Open Virtual Appliance (OVA) image that contains your operating system of choice. Once you have that base image imported or defined in the Image Construction and Composition Tool, you can extend it to create a custom image on top of the base OS image.
After creating your extended image, you can add bundles that represent the software you want to install in your custom image. Simply click on the Software tab of the new virtual image. Click the add icon, and select the bundle that you want to add. You can add as many bundles as you would like to your custom image.
After adding a bundle, it will show up in the Planned list of software for the image. Click on it to display its details in the right side of the screen. You will notice General, Install, and Configuration sections for the bundle. In the Install section, you will find a list of the installation parameters you defined for the bundle. You can provide values for the parameters at this time.
If you click on the Configure section, you will see all of the configuration paramters you specified for the bundle. You can provide default values, and you can specify whether or not these should be configurable by deployers of your custom image. If you mark them as configurable, users will be able to provide values for the parameters at image deploy time, regardless of whether they provision the image using WebSphere CloudBurst, Tivoli Provisioning Manager, or the IBM Cloud.
After you add the necessary bundles and specify installation and configuration data, you can save the image. Upon saving, the image status changes from Synchronized to Out of Sync.
Now you are ready to synchronize the image. To do this, simply click the synchronize icon. This will result in the creation of a virtual machine in the cloud envrionment (VMware or IBM Cloud) you defined in the selected cloud provider. The Image Construction and Composition Tool will then invoke the appropriate installation tasks (per the bundles you included in the image) within the running virtual machine. It will also copy over any configuration scripts you defined in the bundle.
After a while, the synchronization process completes, and the image returns to the Synchronized state. At this point, you are ready to capture the image by clicking the capture icon. This results in the creation of an OVA virtual image with your customizations. When the capture process completes, the image status changes to Deployable.
Once the image is in the deployable state, it is nearly ready to use. If you are using the IBM Cloud as your cloud provider, you can simply mark the image complete by clicking the complete icon. At this point, the image will show up in your private catalog on the IBM Cloud and it is ready to use. If you are using VMware as the cloud provider, you need to export the image. Click the export icon and provide information about an SCP-enabled server to which you want to export the image. Ideally, this location is directly reachable by the WebSphere CloudBurst or Tivoli Provisioning Manager environment into which you will import the image.
You can monitor the export status in a separate window by clicking on a link shown after clicking the OK button in the dialog above. When the export finishes, you are ready to import your new custom virtual image into WebSphere CloudBurst or Tivoli Provisioning Manager.
I hope the last three posts have given you a better idea of what the new IBM Image Construction and Composition Tool is all about. There will definitely be more to come about this tool in the near future, but in the meantime, if you have any questions or comments, please reach out to me. Until then, good luck and full speed ahead on your custom image compositions!
I hardly ever have a conversation about WebSphere CloudBurst, or generally cloud computing for application middleware, without the topic of databases coming up. Databases are such an important piece of nearly every application middleware environment, so users want to be sure that whatever they do for their application servers, they can also do for the databases on which their applications rely. That is why the capability to deploy DB2 from WebSphere CloudBurst has been around for as nearly as long as the capability to deploy WebSphere Application Server.
Even though DB2 deployment capability has been around for a while, there are still some common misconceptions regarding the offering. First, I have talked to a fair number of users who are under the impression that we only offer a trial version of DB2 for deployment via WebSphere CloudBurst. While that was true for the first few months of the offering, that is no longer the case. For several months now, a fully supported, 64 bit, production-ready DB2 image has been ready for use in WebSphere CloudBurst. If you were waiting for a DB2 image that you could go live with, wait no longer!
The other misconception, or rather, point of confusion, arises from the fact that the DB2 image for WebSphere CloudBurst is not, by name, a Hypervisor Edition image. I can assure you that is in name only. The DB2 image looks like and behaves like any other IBM Hypervisor Edition image once you load it into the appliance. You can use it to build and deploy patterns in the same way you use other images in WebSphere CloudBurst. You may just have trouble finding it if you search for 'DB2 Hypervisor Edition' as opposed to 'DB2 Server for WebSphere CloudBurst Appliance.'
Instead of going into further detail, I want to refer you to a blog entry from a fellow IBMer, Leon Katsnelson. Leon is a program director for DB2 and is responsible for the team that develops and delivers the DB2 image for WebSphere CloudBurst. In his most recent post, he provides a nice overview of the image and gives good information for those looking to use DB2 and WebSphere CloudBurst (there is also a bit on cloud computing at the beginning that I think is spot on). Check out Leon's post, and let us know what you think!
One of the key benefits of WebSphere CloudBurst adoption is rapid -- seriously fast -- deployments of middleware application environments. Our users are leveraging the appliance to bring up enterprise-class middleware environments in mere minutes. If you know a little bit about WebSphere CloudBurst, that statistic may be a little surprising considering the appliance dispenses large virtual images from the appliance over the network to a farm of hypervisors. You may ask how the appliance can achieve such rapid deployments in light of the mere physics involved in transferring large amounts of data over a network. The simple answer is caching of course!
WebSphere CloudBurst creates a cache for each unique virtual image on datastores associated with the hypervisors in your cloud. On subsequent deployments of the same virtual image to the same datastore, WebSphere CloudBurst does not need to transfer the image over the wire. It simply uses the virtual disks that are in the cache on the datastore. In the context of the virtual image cache, the deployment process goes something like this:
WebSphere CloudBurst identifies the images necessary to deploy the pattern selected by the user.
WebSphere CloudBurst identifies the hypervisors and associated datastores that will host the virtual machines created during deployment.
WebSphere CloudBurst checks the selected datastores to see if they already have caches for the images it will be deploying. From here, one of two things happens:
WebSphere CloudBurst detects that there is no cache on the datastore and transfers the images over to the hypervisor, thereby creating the cache on the underlying datastore.
WebSphere CloudBurst detects that there is a cache on the selected datastore and uses that cache in lieu of transferring the disk over the wire.
The process may sound complicated, but it is completely hidden from you, the user. You do not need to know how the cache works since WebSphere CloudBurst handles all of these interactions. So, why am I telling you all of this then? As a WebSphere CloudBurst user, it is good to be aware of the cache for two main reasons. First, you need to account for the storage space the cache needs when doing capacity planning for your WebSphere CloudBurst cloud. Second, anytime you upload or create a new image through extend and capture, I would strongly suggest you automatically prime the cache for this new image. You can do this by simply deploying a pattern built on the image to each unique hypervisor/datastore in your environment. This may take a temporary re-arrangement of cloud groups, but it is a simple process, and it guarantees rapid deployments for all users of the new image.
I hope this sheds a little light on a subject we do not discuss too often. As always, if you have any questions, do not hesitate to let me know!
In a recent post, Joe Bohn detailed some of the new capabilities and enhancements that come along with the recently delivered IBM Workload Deployer v3.1. To be sure, there are many valuable new features such as PowerVM support for virtual application patterns, the Plugin Developer Kit, WebSphere Application Server Hypervisor Edition v8, and more. Each of these topics probably merit their own post, but today I want to talk about something I did not mention above. Specifically, I want to talk about the announcements regarding the IBM Image Construction and Composition Tool (ICCT) and what that means for IBM Workload Deployer users.
You may have read an earlier post that I wrote about the ICCT, but allow me a brief overview here. In short, the ICCT enables the construction of custom virtual images for use in IBM Workload Deployer. You use the tool to create virtual images, much like IBM Hypervisor Edition images, and then you can use those custom images (containing whatever content you need) to create your own custom virtual system patterns. The key point about the custom images you create with the ICCT is that they are dynamically configurable. That is, the tool helps you to create the images in such a way that you can defer configuration until deploy time rather than burning such configuration directly into an image. For those of you familiar with virtual image creation, you know this type of 'intelligent construction' is a huge step towards keeping image inventory at a reasonable level.
Okay, enough of a general overview for now. Let's talk about the two new items of note regarding IBM Workload Deployer v3.1 and the ICCT. The first thing you should know is that starting in IBM Workload Deployer v3.1, the ICCT is shipped with the appliance. This means that you do not need to go anywhere else in order to get your hands on the tool to start creating your custom images. You simply log into IBM Workload Deployer and click the download link on the appliance's welcome panel (shown in image below).
Getting your hands on the tool is one piece of the puzzle, but using it is quite another. While the ICCT has been available as an alphaWorks project for some time, that also implies that there has never been official support for the tool. That changes starting with IBM Workload Deployer v3.1. The ICCT is now a generally available product from IBM, and that means that it is fully and officially supported as well. Further, the images you create using the tool are also officially supported for use as building blocks of your IBM Workload Deployer virtual system patterns. For many of you who have been using the ICCT for some time, but have been hesitant to expand use because of the lack of a formal support statement, you should now feel free to charge forward!
I hope this helps clear up exactly what the new Image Construction and Composition Tool announcements that were part of IBM Workload Deployer v3.1 actually mean. I cannot wait to hear about how you all are putting the ICCT to use with IBM Workload Deployer. Finally, don't forget to send us any questions, comments, or other feedback that you may have regarding this or any other new feature in IBM Workload Deployer v3.1!
As many of you well know, virtual images are the foundation of virtual system patterns in IBM Workload Deployer. Whether you are using IBM Hypervisor Edition images or custom-built images produced by the IBM Image Construction and Composition Tool, every virtual system pattern has at least one virtual image as part of its foundation. So, if virtual images are the foundation of virtual system patterns, what is the foundation of these virtual images?
While you could probably make a good argument for a number of different things being the foundation of the virtual image (operating system, other installed software, etc.), I like to think that, at least in the context of IBM Workload Deployer, the activation engine inside the virtual image is the true foundation. Inside this activation engine, you will find a collection of scripts and services that are capable of configuring the virtual machine for use. Not only does this engine perform basic system-level actions like configuring the machine's hostname, IP address, time, and network interfaces, but it also configures the software on the inside of the virtual machine. For instance, the activation engine in the WebSphere Application Server Hypervisor Edition image is capable of fixing up profile information, federating nodes, creating application server clusters, and more. Best of all, in the case of IBM Hypervisor Edition images, you (the user) get all of this right out of the box. There is no logic to perform or administrative tasks to undertake in order for you to benefit from the activation engine. It is simply there!
So, at this point you may ask yourself 'If all of this is included right out of the box, why do I need to care?' That is a fair question, but ultimately I feel it is always important to understand the foundational elements of any technology. In this respect, I do not feel like the activation engine in the IBM Hypervisor Edition images is any different. Lately, I have been telling my users to take at least a little time to understand what the activation engine is and even more importantly, what it is doing for you during deployment. Specifically, I always suggest taking a little time to look at the scripts in the activation engine -- most often found in the /opt/IBM/AE/AS directory of a virtual machine deployed by IBM Workload Deployer.
What can be gained by taking the time to peruse through these scripts? I think most importantly, you will learn what the engine does for you and what you cannot do if you expect the image to deploy correctly. For instance, if you look in some of those activation engine scripts, you will see that it uses the sudo command in several places. While I know many of you may be tempted to remove the sudo command during extend and capture, if you do so it will break the activation engine. I have seen this happen multiple times, and trust me, if you did not know the activation engine used that command it is not necessarily an easy problem to debug. This is a case where the value of at least superficially understanding the activation engine is clear.
Want another example? Okay, consider that you want to run WebSphere Application Server as a user called wasadmin. At pattern deployment time, it is easy enough to supply wasadmin in the appropriate field of the part configuration data and click OK. IBM Workload Deployer deploys the system and voila, WebSphere Application Server is magically running as wasadmin. Everything is fine so far, but let's take this a step further and say that you previously performed an extend and capture, and you installed software components in the image that should be owned by your wasadmin user. It is technically possible to define users during extend and capture and then install software content via that user, but if you also want to specify that user as the WebSphere Application Server administrative user at deployment time, you will run into an issue. This is because the activation engine runs the usermod command during deployment to change the existing and default virtuser into the user that you specify -- in this case wasadmin. If the usermod command attempts to change virtuser to wasadmin but wasadmin already exists as a user on the operating system, the command will not complete properly, and it is very likely you will see further errors downstream. A simpler way to do this is to create the user during extend and capture, install any components via that user, and then delete the user before capturing. You can attach a deploy-time script that fixes up the appropriate settings for wasadmin (like user ID and group ID), and it will run after the activation engine successfully does a usermod and changes virtuser to wasadmin.Problem averted!
In reading some of the above, I fully realize that it may be a little confusing at first. That said, I assure you that there is not much to it at all once you have a basic understanding of the activation engine. With a basic understanding of the activation engine in tow, you will know what you do not need to do (e.g. create profiles, federate nodes, etc.), what you cannot do (e.g. remove the sudo command), and what you can do with a little bit of reconciliation work (e.g. define your WebSphere Application Server administrative user during image extension). I encourage you to take a little time with your next deployment and give the activation engine a once over. You will undoubtedly have a better understanding of the deployment process, and you will ultimately be in a position to most effectively leverage virtual system patterns in IBM Workload Deployer.
Lately, I have run into multiple situations where an IBM Workload Deployer user has been trying to decide exactly how they want to create their customized images for the cloud. Essentially, they have been trying to decide whether to use the native extend and capture capabilities of IBM Workload Deployer, or to pursue the use of the Image Construction and Composition Tool (also included with the appliance). The conversations have been interesting and challenging, but more importantly, they have been a reminder that constructing enterprise-ready environments for the cloud does not happen by magic. It takes thought, deliberate planning, sustainable design, and the tools to carry everything out.
The tools part we have covered. I have every confidence, bolstered by user experience after user experience, that IBM Workload Deployer and associated tools (like the Image Construction and Composition Tool) equip you to build highly customized, cloud-based application environments. In this post, I want to focus in on the thought process that goes into how you decide to build your customized environment. Specifically, I would like to talk about important points to consider as you try to understand whether to use the native extend and capture capabilities of IBM Workload Deployer or the Image Construction and Composition Tool.
To be clear from the outset, I am not trying to provide a decision flowchart in this post. For all intents and purposes, that would be next to impossible. Instead, I want to pose to you some important questions that you should ask of yourself, along with the reasons why I believe those queries to be important. Keeping in mind that this is not an all-inclusive list, here it goes:
Question: Are the customizations that you want to make congruent with an IBM-supplied image?
Reason: One of the first decisions you should make is whether or not you can start with an IBM-supplied image as the base for your customization. You need to know what middleware elements (type and version) make up your environment and what operating system should host that environment (version and distribution). You can match that information against the list of content that IBM supplies. If there is a match, you should start by looking at extend and capture to customize that image to meet your needs. If there is no direct match, you may be looking at the Image Construction and Composition Tool.
Question: Does your custom content supplement middleware content supplied in an IBM image?
Reason: If you simply need to add additional components that supplement software already in an IBM image, I believe it is best to first examine the use of extend and capture. Whether these components are IBM software or not is irrelevant as the extend and capture functionality does not care.
Question: How configurable do you want to make the custom content in your image?
Reason: If you are adding content into the image, you need to think about just how configurable you need it to be. When you use extend and capture, you add the content to an existing image in a manner that pretty well ends up being opaque to IBM Workload Deployer. To configure that content, you need to have script packages and make sure they are part of every pattern you create based on the image. Alternatively, if you use the Image Construction and Composition Tool, you can embed configuration behavior in the image's activation engine, and you can expose deploy-time parameters without needing to include script packages in every single pattern. As an example, if you need to add a monitoring agent into your environment, you would likely do this via extend and capture and end up with a pretty simple script package to configure that agent during deployment. If however, you need to create an image with a custom database, you would likely favor the Image Construction and Composition Tool as you could embed common deploy-time configuration parameters directly in the image. For a database, there are likely to be many more deploy-time configuration parameters that you want to expose as compared to a more simple monitoring agent.
Question: Is your main focus on making operating system changes?
Reason:If your primary focus is on making operating system changes AND the answer to the first question is that your target content aligns well with IBM-supplied images, then extend and capture is where you want to start. Of course, you need to make sure that you can make all necessary changes to the OS with extend and capture, but I will say that this capability is not very restrictive at all.
Admittedly, this is a short list, but I believe it is a good starting point for how you decide upon one approach versus the other. Also, I would be remiss not to point out that these tools are absolutely not mutually exclusive. Many users I work with use a combination of the two approaches. In fact, there are some use cases that call for both tools. Start by creating a completely custom image in the Image Construction and Composition Tool, and then subject that image to the extend and capture process in IBM Workload Deployer to customize it for a particular purpose, team, project, etc. I hope you find this helpful, and I welcome your feedback or thoughts!